Background: The Global Initiative for Chronic Obstructive Lung Disease (GOLD) update 2023 proposed new definitions of chronic obstructive pulmonary disease (COPD) and COPD exacerbation. However, an agreement on the definitions has not been made, either internationally or domestically. This study aimed to reach an agreement between experts on the new definitions of COPD and COPD exacerbation in South Korea. Methods: A modified Delphi method was used to make an agreement on the definitions of COPD and COPD exacerbation proposed by the GOLD update 2023. We performed two rounds of the survey including 15 Korean experts on COPD, asthma, and tuberculosis. Results: More than two-thirds of the experts agreed on 12 of the 13 statements related to the definitions of COPD and COPD exacerbation in the two rounds of the survey. The experts agreed on the definitions of COPD and COPD exacerbation that should be revised in line with the definitions proposed by the GOLD update 2023. However, the experts showed an uncertain opinion on the statement that the definition of COPD includes patients with persistent airflow obstruction due to bronchiectasis. Conclusion Based on this Delphi survey, experts’ agreement was made on the definitions of COPD and COPD exacerbation proposed by the GOLD update 2023.

Background/Aims: We evaluated nailfold capillaroscopy (NFC) of interstitial pneumonia with autoimmune features (IPAF) and compared it with that of patients with connective tissue disease-interstitial lung disease (CTD-ILD) and idiopathic interstitial pneumonia (IIP). Methods: Patients with newly diagnosed as ILD were evaluated using NFC. Baseline demographic, clinical, serological, and high-resolution CT findings were collected. NFC was semi-quantitatively scored with six domains ranging from 0 to 18. In addition, the overall patterns (sclerodermaon-scleroderma patterns) were determined. Results: A total of 81 patients (31 with CTD-ILD, 18 with IPAF, and 32 with IIP) were included. The non-specific interstitial pneumonia pattern was the most common ILD pattern in the CTD-ILD and IPAF groups, whereas the usual interstitial pneumonia pattern was the most common in the IIP group. The semi-quantitative score of the CTD-ILD group was higher than that of the IPAF or IIP groups (5.8 vs 4.2 vs 3.0, p < 0.001, respectively). Giant capillaries and haemorrhages were more frequently present in the CTD-ILD and IPAF groups than in the IIP group. A scleroderma pattern was present in 27.8% of the IPAF group, whereas none of the IIP patients showed a scleroderma pattern. Conclusions NFC findings may be useful in classifying patients with ILD into CTD-ILD/IPAF/IIP.

Background: There is insufficient data on the benefits of empiric antibiotic combinations for hospital-acquired pneumonia (HAP). We aimed to investigate whether empiric antipseudomonal combination therapy with fluoroquinolones decreases mortality in patients with HAP. Methods: This multicenter, retrospective cohort study included adult patients admitted to 16 tertiary and general hospitals in Korea between January 1 and December 31, 2019.Patients with risk factors for combination therapy were divided into anti-pseudomonal non-carbapenem β-lactam monotherapy and fluoroquinolone combination therapy groups.Primary outcome was 30-day mortality. Propensity score matching (PSM) was used to reduce selection bias. Results: In total, 631 patients with HAP were enrolled. Monotherapy was prescribed in 54.7% (n = 345) of the patients, and combination therapy was prescribed in 45.3% (n = 286).There was no significant difference in 30-day mortality between the two groups (16.8% vs.18.2%, P = 0.729) or even after the PSM (17.5% vs. 18.2%, P = 0.913). After the PSM, adjusted hazard ratio for 30-day mortality from the combination therapy was 1.646 (95% confidence interval, 0.782–3.461; P = 0.189) in the Cox proportional hazards model. Moreover, there was no significant difference in the appropriateness of initial empiric antibiotics between the two groups (55.0% vs. 56.8%, P = 0.898). The proportion of multidrug-resistant (MDR) pathogens was high in both groups. Conclusion Empiric anti-pseudomonal fluoroquinolone combination therapy showed no survival benefit compared to β-lactam monotherapy in patients with HAP. Caution is needed regarding the routine combination of fluoroquinolones in the empiric treatment of HAP patients with a high risk of MDR.

Background: Sterility and safety assurance of hematopoietic stem cell (HSC) products is critical in transplantation. Microbial contamination can lead to product disposal and increases the risk of unsuccessful clinical outcomes. Therefore, it is important to implement and maintain good practice guidelines and regulations for the HSC collection and processing unit in each hospital. We aimed to share our experiences and suggest strategies to improve the quality assurance of HSC processing. Methods: We retrospectively analyzed microbial culture results of 11,743 HSC products processed over a 25-year period (January 1996 to May 2021). Because of reorganization of the HSC management system in 2008, the 25-year period was divided into periods 1 (January 1996 to December 2007) and 2 (January 2008 to May 2021). We reviewed all culture results of the HSC products and stored aliquot samples and collected culture results for peripheral blood and catheter samples. Results: Of the 11,743 products in total, 35 (0.3%) were contaminated by microorganisms, including 19 (0.5%) of 3,861 products during period 1 and 16 (0.2%) of 7,882 products during period 2. Penicillium was the most commonly identified microorganism (15.8%) during period 1 and coagulase-negative Staphylococcus was the most commonly identified (31.3%) during period 2. HSC product contamination occurred most often during HSC collection and processing. Conclusions The contamination rate decreased significantly during period 2, when the HSC management system was reorganized. Our results imply that handling HSC products by trained personnel and adopting established protocols, including quality assurance programs, aid in decreasing the contamination risk.

Background/Aims: Most studies on hospital-acquired pneumonia (HAP) have been conducted in intensive care unit (ICU) settings. This study aimed to investigate the microbiological and clinical characteristics of non-ICU-acquired pneumonia (NIAP) and to identify the factors affecting clinical outcomes in Korea. Methods: This multicenter retrospective cohort study was conducted in patients admitted to 13 tertiary hospitals between July 1, 2019 and December 31, 2019. Patients diagnosed with NIAP were included in this study. To assess the prognostic factors of NIAP, the study population was classified into treatment success and failure groups. Results: Of 526 patients with HAP, 379 were diagnosed with NIAP. Overall, the identified causative pathogen rate was 34.6% in the study population. Among the isolated organisms (n = 113), gram-negative bacilli were common pathogens (n = 91), such as Pseudomonas aeruginosa (n = 25), Acinetobacter baumannii (n = 23), and Klebsiella pneumoniae (n = 21). The multidrug resistance rates of A. baumannii, P. aeruginosa, and K. pneumoniae were 91.3%, 76.0%, and 57.1%, respectively. Treatment failure was significantly associated with K. pneumoniae (odds ratio [OR], 3.50; 95% confidence interval [CI], 1.35 to 9.05; p = 0.010), respiratory viruses (OR, 3.81; 95% CI, 1.34 to 10.82; p = 0.012), hematological malignancies (OR, 3.54; 95% CI, 1.57 to 8.00; p = 0.002), and adjunctive corticosteroid treatment (OR, 2.40; 95% CI, 1.27 to 4.52; p = 0.007). Conclusions The causative pathogens of NIAP in Korea are predominantly gram-negative bacilli with a high rate of multidrug resistance. These were not different from the common pathogens of ICU-acquired pneumonia.

Background: The soluble forms of suppression of tumorigenicity-2 (ST2) and galectin-3 have been proposed as novel biomarkers for cardiac fibrosis and heart failure, as well as predictors of cardiovascular events and mortality. However, there are limited data on the association between soluble ST2 and galectin-3 and clinical outcomes in patients with kidney failure on replacement therapy. To determine this, we examined the associations between soluble ST2 and galectin-3 and all-cause mortality and cardiovascular events in patients on hemodialysis. Methods: This study included maintenance hemodialysis patients (over 18 years old) who consented to preserve their serum in the Biobank at our institution between March 2014 and March 2015. We used Cox proportional hazards regression analysis to evaluate the associations between soluble ST2, galectin-3 levels, and clinical outcomes. The primary outcome was all-cause mortality, the secondary outcome was cardiovascular disease, and patients were followed for both outcomes until March 2018. Results: A total of 296 patients were analyzed in this study. The mean age was 57 ± 13 years, and 53.0% were male. Serum concentration of soluble ST2 was significantly associated with higher mortality, after adjustment for confounding factors, but was not associated with cardiovascular disease. Serum galectin-3 level was not independently associated with either outcome after adjustment. Conclusion Elevated soluble ST2 is independently associated with an increased risk of mortality, but not with cardiovascular disease, in patients on hemodialysis. Elevated galectin-3 was not associated with mortality or cardiovascular disease.

Background: Hospital-acquired pneumonia (HAP) and ventilator-associated pneumonia (VAP) are significant public health issues in the world, but the epidemiological data pertaining to HAP/VAP is limited in Korea. The objective of this study was to investigate the characteristics, management, and clinical outcomes of HAP/VAP in Korea. Methods: This study is a multicenter retrospective cohort study. In total, 206,372 adult patients, who were hospitalized at one of the 13 participating tertiary hospitals in Korea, were screened for eligibility during the six-month study period. Among them, we included patients who were diagnosed with HAP/VAP based on the Infectious Diseases Society of America (IDSA)/American Thoracic Society (ATS) definition for HAP/VAP. Results: Using the IDSA/ATS diagnostic criteria, 526 patients were identified as HAP/VAP patients. Among them, 27.9% were diagnosed at the intensive care unit (ICU). The cohort of patients had a median age of 71.0 (range from 62.0 to 79.0) years. Most of the patients had a high risk of aspiration (63.3%). The pathogen involved was identified in 211 patients (40.1%). Furthermore, multidrug resistant (MDR) pathogens were isolated in 138 patients; the most common MDR pathogen was Acinetobacter baumannii. During hospitalization, 107 patients with HAP (28.2%) had to be admitted to the ICU for additional care. The hospital mortality rate was 28.1% in the cohort of this study. Among the 378 patients who survived, 54.2% were discharged and sent back home, while 45.8% were transferred to other hospitals or facilities. Conclusion This study found that the prevalence of HAP/VAP in adult hospitalized patients in Korea was 2.54/1,000 patients. In tertiary hospitals in Korea, patients with HAP/VAP were elderly and had a risk of aspiration, so they were often referred to step-down centers.

Purpose: Our previous work demonstrated that miRNA-495 targets SOX9 to inhibit chondrogenesis of mesenchymal stem cells.In this study, we aimed to investigate whether miRNA-495-mediated SOX9 regulation could be a novel therapeutic target for osteoarthritis (OA) using an in vitro cell culture model. Materials and Methods: An in vitro model mimicking the OA environment was established using TC28a2 normal human chondrocyte cells. Interleukin-1β (IL-1β, 10 ng/mL) was utilized to induce inflammation-related changes in TC28a2 cells. Safranin O staining and glycosaminoglycan assay were used to detect changes in proteoglycans among TC28a2 cells. Expression levels of COX-2, ADAMTS5, MMP13, SOX9, CCL4, and COL2A1 were examined by qRT-PCR and/or Western blotting. Immunohistochemistry was performed to detect SOX9 and CCL4 proteins in human cartilage tissues obtained from patients with OA. Results: miRNA-495 was upregulated in IL-1β-treated TC28a2 cells and chondrocytes from damaged cartilage tissues of patients with OA. Anti-miR-495 abolished the effect of IL-1β in TC28a2 cells and rescued the protein levels of SOX9 and COL2A1, which were reduced by IL-1β. SOX9 was downregulated in the damaged cartilage tissues of patients with OA, and knockdown of SOX9 abolished the effect of anti-miR-495 on IL-1β-treated TC28a2 cells. Conclusion We demonstrated that inhibition of miRNA-495 alleviates IL-1β-induced inflammatory responses in chondrocytes by rescuing SOX9 expression. Accordingly, miRNA-495 could be a potential novel target for OA therapy, and the application of anti-miR-495 to chondrocytes could be a therapeutic strategy for treating OA.